Machine for sharpening with a grindstone circular and band saws



Mach 17, 1925. v 1,530,378

J. T. LANFRANCHI MACHINE FOR SHARPENING WITH A GRINDS TONE CIRCULAR ANDBAND SAWS Filed Jan. 10, 1921 4 Sheets-Sh et 1 Fig,1.

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J. T. LANFRANCHI I MACHINE FOR SHARPENING WITH A GRINDSTONE CIRCULAR ANDBAND SAWS March 17. 1925. 1,530,378

Filed Jan. 10, 1921 4 Sheets-Sheet 2 Fig.2.

March 17, 1925. r 1,530,378

J. T. LANFRANCHI N MACHINE FOR SHAHPENING WITH A GRINDSTONE CIRCULAR ANDBAND SAWS Filed Jan. 10, 1921 4 Sheets-Sheet 5 March 17,1925. 11,530,378

J. T. LANFRANCHI MACHINE FOR srmnrzmue WITH A emunswom: CIRCULAR ANDBAND SAWS Filed Jan. 10, 1921 4 Sheets-Sheet 4 Fig .7.

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lNVE/VTOP Patented Mar. 17, 1925;

UNITED STATES] v 1,530,37 PATENT" OFFICE.

JEAN ToirssiuN'r LANFRANGHI, or PARIS, FRaNcn, ASSIGNOR TO CHARLESeAsroN I I ,vnYssInRiai, or sr. CLOUD, FRANCE.

. MACHINE non sHAnrENING WITH a GRINDSTONE CIRCULAR ANn BANns ws.

r Application filed JanuaryIO, 1921. Serial No. 436,288.

To all whom it maycoacern: I Be it known that LJEAN ToUssAI 'r LAFRANOHI, of -1 Place Martin-Nadaud, Paris,

France, engineer, have invented a l\l[achinearranged a blade 6 adaptedto support the" for Sharpening with a Grindstone Circular and Band Saws,of which the following is a full, clear, and exact description.

This invention relates toa machine for automatically sharpening circularandband: saws having teeth of any profile and sep arated from each otherby anyiii'itervals.

The new machine is extremely simple andthe mechanism allows to obtain amachine which is durable and of low cost.

This machine is essentially characterized rocking slide the movement ofwhich is controlled by a cam having a profile corresponding to that ofthe tooth of the saw to be sharpened.

by a saw guide-support, of suitable height, constituted by a kind ofautomatically closing clasp.

by hand for conveniently eflecting with precision'the various necessaryadjustments.

The invention is illustrated, by way of example only, in theaccompanying drawing,ii1 which: I

Fig.1 is an elevation of the machine. Fig. 2 is a corresponding planview. Fig. 3 is an elevation of the rear side.

Fig. 5 is a section made according to line AAofFig. 1. 1

Fig 6 is a section made accordingto line 13-13 of-Fig. 3. o a, i Fig. 7is a diagrammatic view showing the curves described by the grindstone ateach tooth.

As illustrated in table 6.

the fixed side of the; saw supporting clasp. This plate carries anlaxisof oscillation (Z by an. inclined grindstone carrier integralv with areciprocating carriage guided on a.

The machine ischaracterize'd, moreover, 5

rod f relatively to the saw.

The machine comprises also a drivingde} vicepermitting to' rotate thesaid machine 'low'of easil removin the rindstone it is stationary.

Fig. 4 is a side view. forremoving the axis 2' by longitudinaldisthedrawing, the; new machine comprises a frame (L supporting a,

On one side ofthe machine is arrangedan upright c carrying a plate 0constituting] on hich rotates a frame (Z forming the movable part of theclasp 'which is pressed against the fixed partby coi interweightsd orsprings. i

Betweenthe plate 0 .and the frame dis saw Sand the height of which canbead-;

v justed by means of handle screws e passing through vertical slotsprovided in the frame. The saw, fitted in the saw guide clasp abovedescribed, moves forward periodically totheextent of one'tooth, throughtheme dium of a thrust or push rod mounted on. a lever f rotating on afixed axis f integral with the support carried by the frame a.

' This lever is actuated by a link 9 hinged on.

a crank-pin 9 presented by a disk 7L1 fast on the cam shaft 71. Thiscrank-pin, which constitutes an eccentric, can be axiallydisplacedon thedisk if, so as to permit of ad justingthe stroke of the link 9 and,conse- -quently,.that of the rod f, according to the spacing apart ofthe teeth. 'On the other hand, the liiik'g isconnected to the crank- 1 1two arms, as Shown in gsupporting the axis of the grindstone. In "orderto alloosely mounted on the axis 41 which is. smooth. A pin 5 isadapted. to manipulate it easily. .A setlscrew i holds'the said axis Itsuffices to unloose this screw integral witha rod F ig, 3, engaged in aI sleeve forming a part ofthe carriage This rod is hollow adjacent toits upper end and internally screw-threaded to receive a screw jcarrying a hand Wheel 7' by means of which it may be rotated, thuscausing the I .grindstone-carrier to rise or lower.

. The rod is guided in its upward and downward movement by a screw'j theend of which is engaged in a longitudinal groove 3' in this rod, Figs. 3and 6.

Tlie'said rod 7 is provided with two'otliei.

similar grooves f, j arranged on the opposides of the first groove,allowing to give to the grindstone a certain inclination relatively tothe saw.

The carriage Z: can have a reciprocating n'iovement on a slide 7. Thismovement is controlled'by a link Z hinged on a pin on which can occupyseveral positions on a. crank m fast on a shaft n; this shaft isactuated by the cam shaft by means of two pinions a and h ,'Fig. t.

The slide Z can rock on an axis Fig. 1, carried by a support 76 on thisaxis is also mounted a lever 0 on which rests the slide. This levercarries, at one end, a roller 0 Fig. l, in contact with a cam 79 fast onthe cam shaft it and at the other end, a screw 0 Fig. 1, on which reststhe slide and adapted to limit" the downward movement of the grindstone.

The cam shaft 71 carries a pulley M, Fig. 4, on which passes a belt 71-driven by a pulley 0' faston the driving shaft q.

On the end of this shaft (1 is loosely mounted a pulley 1" onwhiclrpasses any driving belt. This pulley can be clutched with theshaft g, by means of a claw sleeve r fitting in corresponding notches ofthe hub of the pulley. The sleeve r is displaced by a fork r terminatinga lever s, Fig. 3, pivoting on a fixed axis .9 This lever is controlledby a clutch lever t terminated by a fork engaged on the end of the lever's.

The shaft Q is hollow and within this shaft is arranged a short shaft u,Fig. 4, car rying a hand wheel a and provided with a tenon 14- Thelatter may fit into a notch g of the shaft Q provided with an incline onone of its sides.

On the shaft (1 is fastened another pulley 9 carrying a belt 9 passingon a pulley v). 3; the latter is rigidly secured on a. shaft 1 arrangedunder the machine and carrying a groove pulley '0 on which passes atwisted belt a". The branches of this belt pass on two other groove.pulleys :0 and carried by a guide 0"" of adjustable height and servingas stretcher. The belt in actuates a pulley 09* fast on the hub of thegrindstone 2', Fig. 1.

The operation is as follows:

If a band saw is to be sharpened, this saw is placed in the guide systemand for that purpose the movable part (i of the clasp is opened and thesupporting member 6 is adjusted to the necessary position for causingthe saw to present its teeth above the table at the required height,

If a circular saw is to be sharpened, the part (Z of the clasp is takenoff, by removing the axis (Z which, for that purpose is so arranged asto be capable of being instantaneously taken away; the centralperforation of the saw is then placed on an axis 0 carried on theupright c. The height of the support of this aXis is adjusted accord ingto the size of the saw.

The shaft It being provided with a cam corresponding to the shape of theteeth of the saw to be sharpened, the machine is adjusted.

In order to do this, the operator acts on the hand wheel 14 thus causingthe members of the machine to rotate slowly.

He can then see easily and without danger the curve described by thegrindstone. If necessary, he modifies this curve by changing theposition of the pin m in the crank m so as to vary the stroke of thecarriage 70 on the slide Z.

This adjustment which, in the other sharpening machines provided with agrindstone, is a long and delicate operation, is,

on the contrary, in the new machine, very easy and rapid, as it sufficesto act on one screw only, located withinreachof the hand and the effects.of which are constantly visible.

The operator adjusts also the stroke of the thrust or push rod f whichmust be equal to the spacing apart of the teeth and for that purpose hechanges if necessary the position of the pin 9 Then, he suitablypositions the thrust or push rod according to the position of the saw,by rotating the returning screw of the slide-block 9 In order to verifythe extent of the stroke of the carriage j, a nut 0 engaged on the screw0 may be unscrewed so as to bring this nut in contact with the table andto move the rollerw away from the cam 79.

In this position, the carriage Z". effects its to-and-fro movementswithout oscillation.

Vhen the various adjustments have been effected the operator pushes theoperating lever 2f,- the lever s rocks on its axis and brings the tenonsof the sleeve r in engagement with the corresponding notches of the hubof the pulley 1. He thus renders the shaft (1 integral with the drivingpulley 1' and determines the starting. The incline of the notch pushesback the tenon 11 thus disengaging the shaft u of the handwheel from theshaft The machine can be provided with a funnel for receiving the emerydust, this funnel being arranged behind the grindstone; an aspirator,arranged at any point whatever of the machine, can lead away the emervdust and evacuate it outside or in a suitable collector. a

Figure 7 shows different profiles of saw blades which may be sharpenedby means of the new machine and the corresponding curves C C C 0*described by the on erative edge of the grindstonc. It. will be notedthat by the combination of the toand-fro movements of the carriage andthe rocking movement of the slide, controlled by the cam, these curvescanbevery different and absolutely suited to the shape of the teeth.

In case the shown at 0 Fig. 7, the screwv 7' is unloosened out the rod jis caused to rotate on itself,

so as to bring one or the other of thegrooves o f, j opposite this screwwhich is re-tightened. There is thus obtained a cut inclined in onedirection or the other.

The above arrangements are given by Way of example only the forms,dimensions and materials used and all'detail arrangements may be variedaccording to the circum-.

stances Without departing thereby nature of the invention.

Claims: y

1. In a machine for sharpening saws, an inclined grindstone carrier, arocking slide from the on which said carrier has a to-and-fro,

motion, means for moving the carrier on the slide at each stroke forsharpening a tooth on a saw and means for rocking the slide while eachtooth is beingsharpened.

2. In a machine 'for sharpening'saws, an

inclined grindstone carrier, a rocking slide on which said carrier has ato and fro motion, means for moving the carrier on the slide forsharpening the teeth of a saw, and a cam for rocking the slide, the camhaving a profile corresponding to the profile of a saw toot-h.

In a machine for sharpenlng saws, an

' inclined grindstone carrier, a rocking slide on which the carrier hasa tO-and-fromotion, means for imparting the to-and-fromovement to theslide, and means for rocking the slide, said means including a leverengaging the slide, and a cam for operating the said lever.

4. In a machine f or sharpening saws, an

' inclined grindstone carrier, a rocking slide on. which said carrierhas a to-and-fro motion, means for moving the carrier on the slide,means for rocking the slide, said means comprising a lever engaging theslide and a cam engaging thelever, and'adjusting means to vary thestroke ofthe grindstone carrier according to the distance from point topointof the saw teeth.

5. In a machine for sharpeningsaws, an

inclined grindstone carrier, a rocking slide on which said carrier has ato-and-fro motion, means for moving the carrier on the slide, means forrocking the slide, said means rocking the slide While each tooth isbeing sharpened and comprising a lever pivoted intermediate ofits endsand carrying atone end means for engaging the slide, I and a-cam foroperating said lever,.-means for pushing forward the saw periodically tothe extent of one tooth,and means to varythe advance of the saw.

6. In a machinefor sharpening saws, a

teeth. shouldbe bevelled, as

lever, v

drive shaft, an inclined carrier, a grindstone mounted in the carrier, apivoted slide on which said carrier is movable, means for operatingthegrindstone and carrier from the drive shaft, a hand Wheel foroperating the operatlng means, a clutch device for connecting'the handwheel with the drive shaft, and means for rocking the slide on itspivot-as each tooth is sharpened, said means comprising a lever pivotedintermediate of its ends and having at one end adjustable means forengaging the slide,v and a cam engaging the. other end ofthe lever.

7-. Ina machine for sharpening saws, a grindstone, a movable carriertherefor, a

pivoted slide for saidcarrier, means to re-,'

ciprocate the carrier on the slide, and means I to rock the carrier andslide about the pivot,

said means rocking the carriers as each tooth is sharpened andcomprising a lever pivoted intermediate of'lts ends and having on oneendadjustable means for engaging the slide and a cam engaging the otherend of the 9. In a machine for'sharpening saws, a

reciprocating grindstone carrier, a rocking slide on which thenCfLII'lGI' is mounted, a

' pivoted lever having at one end means for loosely engaging theunderside of the slide,

means for operating the lever, and means for disengaging the said leverfrom ing means.

10. In a machine for, sharpening saws, a reciprocating grindstonecarrier, a pivoted slide on which the carrier is mounted, a pivotedleverhavin ga screw in one end for loosely engaging the underside of theslide, a cam engaging the other end of the'lever,

and means for disengaging the lever ,froni ,thecam. I I v o A 11. Inamachine forsharpening saws, a hollow revoluble shaft, a shaft slidablein the hollow shaft and having a hand wheel, cooperating means on saidshafts for turnits operat- L ing theholloW shaft from the shaft havingthe hand wheel, as driving 'pulley'loosefo'n the hollowshaft, and aclutchfor connecting the pulley to the shaft. The foregoingspecification Machine for sharpening with a grindstone circular and bandsaws si ned b me this 17th day-of December, 1920.

JEAN 'ro ssAiN'r LANFRANGHI.

